Zimbabwe: TRB Develops Energy Efficient Barn

Source from:  The Herald 09/01/2015

WORRIED that deforestation could ultimately be bad for business as well as for the environment, the Tobacco Research Board (TRB) has released a new barn design, the kutsaga barn, hoping to encourage farmers to use more fuel-efficient methods of curing their crops.

The kutsaga barn is still based

on rocket principles, but is a much finer improvement on the rocket barn that was introduced not more than five years ago.

TRB chief executive, Dr Dahlia Garwe, said the new barn aims to improve energy efficiency, cut firewood use and minimise pollution when curing tobacco leaves.

The rocket barn did all that, but the kutsaga barn does it better, she said. The barn is currently being rolled out in Marondera and Karoi, key tobacco producing areas.

"The new barn is bigger in capacity. Although it takes in more in terms of quantity of tobacco at a time, it is actually more efficient than the rocket barn in that it will burn less fuel per kilogramme of tobacco," said Dr Garwe last week, by telephone.

The rocket barn derives its name from its ability to draw in dry air using exhaust smoke, rather like a rocket which gains its upward thrust from exhaust. As for the kutsaga barn, well, the TRB "is looking for a much nicer name," she said.

Zimbabwe is the world's largest producer of flue-cured tobacco after China, Brazil and the United States.

However, with the number of small-holder farmers growing tobacco tripling to 100 000 since 2011, plantation forests and natural woodlands - key to stabilising the climate at both micro and macro levels - have suffered great damage.

Farmers destroy a total of almost 50,000 hectares of forest each year gathering wood to cure tobacco, according to the Forestry Commission.

This is due to ignorance, poor farming practices and, until recently, a lack of alternative options.

The rocket barn has a grass insulation 50 mm thick on its higher parts meant to boost efficiency.

With the new barn, it is the bottom of the firebox that is insulated using broken pieces of kaylite, making it much more efficient, said Munanga.

The kutsaga chimney is built inside the barn to make use of waste heat. That compares with the rocket barn's larger diameter-sized chimney, which removes smoke from the furnace and expels moisture from the barn.

Costing just $782, many farmers will find the new barn much cheaper to build compared to the rocket barn, which costs $1 600.

Centralised curing

Some experts believe there is a better way of tackling tobacco-related deforestation - centralise all curing, make it communal, they say.

This way, the industry will minimise the existing chaos which allows each of the 100 000 small growers to cure their own leaf using illegally obtained fuel-wood, argues Mr Tich Mushayandebvu, head of operations, UN Industrial Development Organisation in Harare.

"Instead of the small farmer trying to cure their crop, and doing a terrible job of it, in the end losing the crop's value, that tobacco can be transported to a central place where it can be cured more efficiently to retain its value, giving the farmer a better return," said Mr Mushayandebvu, in an interview.

His choice of energy for such a centralised curing plant is solar, helping to cut the current levels of deforestation linked to tobacco production. But just how could such a plan work, especially in an industry punctuated by individualism and distrust? Who will run the centralised curing stations?

"My thinking is that this has to be a privately operated system," said Mushayandebvu. Enditem